Ways to improve corrosion resistance of welded joints Laser cladding welding machine

Date:2022/5/13 9:37:44 / Read: / Source:本站

Ways to improve corrosion resistance of welded joints Laser cladding welding machine

The improvement of corrosion resistance of welded joints is a comprehensive subject. From material selection, design, manufacture, protection to operation and maintenance of the structure, enough attention must be paid to each link in order to achieve the desired effect. www.dwinauto. com

Several Links to Improve the Corrosion Resistance of Welded Joints
1) Reasonable selection of structural materials and welding materials The corrosion resistance of structural materials can be found in general corrosion manuals, but the corrosion resistance of welded joints must be determined by tests. Welding materials used under corrosive conditions have no systematic data for reference. Special attention should be paid to the reasonable matching of physical and chemical properties, mechanical properties, especially corrosion resistance of welding materials and structural materials (base metal), so as to meet the needs of the given requirements. Determine the requirements of the corrosion system . www.dwinauto.com

2) Rational design of welded structure First of all, have a general understanding of the type of corrosion that the structure may produce under a given working condition, and then start a targeted design on this basis. Common guidelines that must be followed in the design of corrosion-resistant structures include correct strength calculations, avoiding stress concentrations and arranging welds in high-stress areas; minimizing stiffness in parts that are particularly sensitive to corrosion and avoiding junctions or areas that may cause excessive residual stress: Avoid structural dead zones that impede fluid flow and drainage (see Figure 7-28), etc. www.dwinauto.com

3) For a reasonable welding process, it is necessary to clarify that the anti-corrosion structure is different from the general structure, and there are stricter requirements on the manufacturing process. In addition to the correct selection of welding materials, the welding process also includes the selection of welding methods and line energy, the determination of welding sequence, the control of weld fusion ratio, and the prevention of welding defects. Prevention and elimination of residual stress and stress concentration, etc. www.dwinauto.com

5) The corrosion inhibition treatment of the medium removes or reduces the harmful components in the medium that can promote corrosion, and sometimes a corrosion inhibitor can be added. www.dwinauto.com

6) Electrochemical protection of the structure Cathodic protection The structure is connected to the negative pole of the DC power supply, so that it is protected in a cathodic polarization state, which is called the impressed current cathodic protection method. On the structure, a metal with a negative potential (such as a zinc alloy on the hull) is used as the anode to achieve the purpose of cathodic polarization, which is called sacrificial anode protection. When large-scale structures are protected by applied current, the required current density should be determined according to the actual potential of different parts, and attention should be paid to controlling the protection potential to keep it within a safe range to avoid hydrogen embrittlement caused by excessive negative potential. www.dwinauto.com

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